Hospital-Based Study of Severe Malaria and Associated Deaths in Myanmar

Article excerpt

Malaria is a major public health problem in the WHO South-East Asia Region, where an estimated 23 million new cases occur annually. The disease is thought to cause 34 000 deaths each year in the region (1) and in Myanmar is a threat to about 60% of the population. In 1994 about 800 000 clinical cases of malaria and 4377 deaths from the disease were reported in Myanmar. However, estimates of the number of malaria cases and deaths in Myanmar were much higher and amounted to 3 475 085 and 6565, respectively, in 1994. At present, after several years of relative improvement, severity and mortality rates of malaria are increasing in the country.

Information on malaria as a clinicoepidemiological phenomenon is limited (2, 3). It raises a number of methodological issues such as definition, detection and monitoring of severe malaria, association of severity and deaths with risk factors and assessment of malaria mortality (4). Therefore, there is an urgent need for reliable clinicoepidemiological information on malaria as a life-threatening disease to understand better the underlying causes of its severity and related deaths, for policy-making, planning, monitoring and evaluation of disease-specific interventions.

The present study was carried out to identify factors that may contribute to malaria deaths so that guidelines can be set up to monitor and control the severe forms of the disease in Myanmar.

Materials and methods

Study area

The study was carried out in Myanmar in the following township hospitals, which reported large numbers of malaria deaths: Kalay, Tamu, Kawlin, Katha and Kalewa townships of Sagaing division; Yegyi township of Ayeyarwady division and Taunggyi, Yauksauk, Thibaw, Kyaukme, Lashio, Momeik townships of Shan state.

The study area is characterized by endemic and seasonal forest-related malaria, with Anopheles minimus and A. dirus being the principal vectors. The most prevalent parasite species, Plasmodium falcipamm, which is resistant to chloroquine, sulfadoxine--pyrirnethamine and mefloquine, also occurs in this area. The published malaria mortality and morbidity rates were in the range 19.03-45.84 per 100 000 population and 12.52-63.78 per 1000 population, respectively, in this area in 1994.

Hospital-based surveillance for severe and complicated malaria cases

Between July and December 1995, a total of 959 malaria cases (653 adults and 306 children) were admitted to the selected township hospitals in Sagaing, Ayeyarwady and Shan divisions/state. The majority of hospital malaria admissions were straightforward cases, admitted for social rather than medical reasons. Most of the severe and complicated malaria cases within the study area were admitted to township hospitals. A total of 101 severe malaria patients with impaired consciousness and severe anaemia were identified by screening the admissions to inpatient departments. The patient's name, date of admission, age, sex, address, occupation, history of illness before admission, antecedents regarding malaria exposure/protection, clinical features on first medical examination, initial laboratory findings, parasitological examination during hospitalization, provisional/final diagnosis and outcome were recorded on a standard form. Blood samples were taken for the detection of malaria parasites and determination of haemoglobin level. Thick blood smears were Giemsa-stained. The number of parasites per 200 leukocytes was multiplied by 40 to give a quantitative count per [micro]l.

Local residents with a primary diagnosis of falciparum malaria were included in the study. All malaria cases with impaired consciousness and severe anaemia (5, 6), as the subgroups of patients with severe and complicated malaria reported within the study area, were subdivided into two groups as follows: